The US is in the midst of an obesity epidemic, affecting young children. The pediatric primary care setting is an ideal place to address this problem since most families have frequent contact with their pediatrician and a child's health status is regularly assessed in this setting. Recommendations for treating children with a body mass index (BMI) over the 85th percentile in the primary care setting have been developed by an Expert Committee on childhood. Programs are needed that meet the recommendations from the Committee, which include: 1) beginning treatment as young as possible; 2) focusing on the family, with the parent being the primary change agent for treatment; 3) using behavior modification techniques to change eating and activity behaviors; and 4) making 2 or 3 very specific changes in diet and activity at one time. Thus, the aim of this R21 application is to develop, implement, and evaluate a 6-month behavioral childhood obesity intervention that meets the Committee's recommendations and can be implemented in a primary care setting. A second aim of this project is to determine which eating and activity behaviors should be targeted in the intervention. One hundred thirty-five children, aged 4 to 8 years with a BMI > 85th percentile, assessed and referred by their pediatricians, will be randomized to one of three conditions: 1) a newsletter condition; 2) a Behavioral Parenting Program that increases physical activity (60 min/day) and decreases sweetened drink consumption (< 3 servings/week) (Traditional); or 3) a Behavioral Parenting Program that reduces TV watching (< 2 hours/day) and increases low-fat milk consumption (2 servings/day) (Substitutes). Follow-up assessments on weight, height, and standardized BMI (z-BMI), the primary dependent variable, will be conducted at 3, 6, 9, and 12 months. Pediatricians will provide follow-up letters to families, regarding weight and height status, following the assessments. This pilot study allows us to determine the feasibility and efficacy of a pediatric obesity intervention that optimizes the role of the pediatrician and meets the Committee's recommendations for treatment in a primary care setting. Moreover, by comparing the effects of targeting the traditional or substitute behaviors, data will be obtained for a power analysis for a full-scale trial of the effects of these two approaches on long-term weight loss.